Mahogany Duns

This is by far the most important species of Isonychia. Many angling books once split its credit with the species Isonychia sadleri and Isonychia harperi, but entomologists have since discovered that those are just variations of this abundant species.

See the main Isonychia page for more about these intriguing mayflies.

There are many species of these small mayflies, and some of them produce excellent hatches. They include some of the first mayflies to hatch in the Spring and some of the last to finish in the Fall.

Their size makes them difficult to match with old techniques. In the 1950s Ernest Schwiebert wrote in Matching the Hatch:

"The Paraleptophlebia hatches are the seasonal Waterloo of most anglers, for without fine tippets and tiny flies an empty basket is assured."

Fortunately, modern anglers with experience fishing hatches of tiny Baetis and Tricorythodes mayflies are better prepared for Paraleptophlebia.

Paraleptophlebia adoptiva is by far the most important species of this genus in the East and Midwest. It's hard to make sense of so many other species, but some can be considered in groups because they often hatch together:

• Paraleptophlebia mollis, Paraleptophlebia guttata, and Paraleptophlebia strigula complement each other in the East in late spring and early summer.


• Paraleptophlebia debilis and Paraleptophlebia praepedita occur together in the East in the fall.


• Paraleptophlebia debilis and Paraleptophlebia bicornuta
occur together in the West in the fall.